1. Field of the Invention
The present invention relates to an overhead projector and, more particularly, to an overhead projector of the type having a projection unit supported by a swingable member which is swingably attached to a main body of the overhead projector.
2. Description of the Prior Art
An overhead projector of the type mentioned above has been known. This known overhead projector has suffered from a problem in that the swingable member, which supports the projection unit at the free end thereof, may accidentally fall down onto the main body, which produces an impact or shock resulting in serious damage to a Fresnel lens incorporated in the main body and/or to the projection unit carried by the swingable member. This problem is serious particularly when the overhead projector is designed such that the projection unit can be selectively set either in a projecting position on the extreme end of the swingable member or in a storage position, because if the swingable member falls down with the projection unit set in the projecting position, the projection unit drops directly onto the main body, increasing the degree of seriousness of the damage.
In order to overcome this problem, it has been proposed to connect the swingable member to the main body through a suitable resilient means which resiliently urges the swingable member such as to prevent the falling of the swingable member. Such a resilient means, however, can not produce a force large enough to prevent the accidental fall of the swingable member, due to restrictions concerning the location and size of the resilient means.